1. Field of the Invention
The present invention relates to a feed mechanism for feeding a web, such as a printing medium of a printer, from a roll and, more particularly, to a web feed mechanism which permits either continuous or stepwise feeding of a web of small thickness.
2. Description of the Prior Art
Known feed mechanisms of this kind include only a dragging mechanism that simply resists web roll unwinding, e.g. by rubbing the outermost winding of the web. When such a feed mechanism is operated for stepwise feeding, a web being fed may overrun between feeding steps and become slack on its running path. As a result, the tension applied to the web on the running path cannot be constant, and this could cause problems, like the web making noises and/or moving in an undulating manner or wrinkling, tearing, etc.